1. Field
The present disclosure relates generally to joints and, in particular to forming joints between a thermoplastic material and a metal. Still more particularly, the present disclosure relates to a method and apparatus for treating a metal to join the metal and the thermoplastic material when forming a joint.
2. Background
Aircraft are being designed and manufactured with ever increasing percentages of composite materials. Composite materials may be tough, light-weight materials created by combining two or more functional components. For example, a composite material may include reinforcing fibers bound in a polymer resin matrix. Resins used in composite materials may include thermoplastic or thermoset resins. A thermoplastic material may become soft upon heating and may harden upon cooling. A thermoplastic material may be able to be repeatedly heated and cooled. A thermoset material may become hard when heated. The fibers may be unidirectional or may take the form of a woven cloth or fabric.
In some applications, it may be desirable to join a thermoplastic material, such as a thermoplastic composite, to a metal. Currently, thermoplastic materials may be joined to metals using fasteners or adhesive. However, using fasteners to join thermoplastic materials and metals may undesirably add additional weight to a joint. Further, joint design or material properties may make fasteners undesirable.
Material characteristics of thermoplastic materials, such as surface tension, may make adhesives undesirable in thermoplastic joints. Further, material properties of an adhesive, such as degradation temperature, may cause adhesives to be undesirable in certain manufacturing processes. Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.